


In The Heat Of The Moment Comes Clarity

by Ironkhaleesi



Series: Little Sister!Reader Incest - Marvel/Supernatural/Sherlock/Vikings/The Originals/Game of Thrones/Teen Wolf/King Arthur: Legend of the Sword [20]
Category: Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Angst, F/M, Incest, Smut, a/b/o dynamics
Language: English
Status: Completed
Published: 2017-12-09
Updated: 2017-12-09
Packaged: 2019-02-12 13:03:51
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,973
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12959805
Author URL: https://archiveofourown.org/users/Ironkhaleesi/pseuds/Ironkhaleesi
Summary: All his life, Bucky had managed to keep his unorthodox feelings for his baby sister under wraps - until he got an apartment with you. Unable to keep his threadbare control in check, he up and leaves for two months without warning. It's not until he's wracked with guilt and in agony of your separation that he finally returns, and when he does, you're right in the middle of your heat and crying out for him.





	In The Heat Of The Moment Comes Clarity

It was settled. Bucky was the worst person in the history of … well, everything. Getting an apartment for just him and you was the worst thing he could have done. He knew it when he thought of it. He knew it when he signed the lease papers. But damn if he didn’t want to keep you by his side every second of his life.

Everyone else just thought he was the over-protective big brother who fretted over his baby sister. It was sweet and endearing and everyone loved him for it. Most of all you.

Bucky knew the truth. The deep, dark, twisted truth. He wanted to fuck you. Make love to you. Claim you in front of everyone. He wanted your neck to bear his mark. He wanted to buy a house with you. Live a life with you. Pay taxes with you. Cook with you. Grow old with you. 

He wanted everything a man was never meant to have with his sister. It was his greatest sin, and yet, when you’d asked to live in an apartment away from the Avengers – away from the Alphas who were becoming overbearing due to your Omega status – the first thing Bucky had done was get an apartment just for you and him. The deal being that he would stay at the Tower whenever your heat started. 

He lasted a month living alone with you. After that, he couldn’t look himself in the mirror. At least at the Tower, there was always distractions. If his eyes lingered on you too long, Tony’s self-assured ramblings would snap him out of it. If he touched you a little too much, having people around would stop him.

There were contingencies in place that prevented him from entertaining his fantasies. When it was just you and him, they weren’t there. Nothing to keep him in check. He became more affectionate, more aggressive. He behaved less like your big brother and more like your Alpha. 

The last straw for Bucky was when you’d gotten sick and Steve had visited to give you some soup and meds. Bucky had nearly taken his head off just for getting his scent all over your bedroom. Bruce and Clint, being Betas, had been the only ones allowed in your apartment after that. Bucky was just too aggressive.

The kind of aggressive that Alphas became when their mates were unclaimed by them.

He’d packed his bags within the week and left for the Tower. Two months he spent away from you. Two months he spent avoiding your calls and visits. Two months he spent in agony.

It wasn’t until the incident with Steve that the rest of the team began to suspect something was off about Bucky’s feelings towards you. That he didn’t just see you as his baby sister, but as his Omega as well.

They tried to help, but that didn’t last long when Bucky laid Tony out for suggesting a psychologist. The only advice Bucky took was from Natasha.

“Talk to her,” she’d said.

It was the simplest thing in the world, and it could ruin Bucky.

On the one hand, you could find Bucky’s feelings disgusting. It would ruin your close bond but at least Bucky would never be tempted to act on his feelings. On the other hand … you could feel the same. You could justify his feelings. You could forgive him. Tell him it was okay. 

His self-control only stretched so far. If he had your consent … he was afraid he would do something unforgivable in the eyes of the world. But he needed to do something. 

So here he was, sitting on the couch in your shared apartment, and it dawned on him just how fucked he really was. He should have called before he showed up. He should have checked the date.

The scent had hit him the moment the door opened, and by the time he’d made it to the couch and collapsed onto it, he was rock hard in his pants. You were smack bang in the middle of your fucking heat. 

He was really the asshole cherry on top of the asshole fucking cake. First, he lusts after his baby sister. Then, he abandons you for two months without warning because he can’t control himself. Now, when he does come back, it’s in the middle of your heat and he knows, beyond any doubt, that he is not leaving that apartment without claiming you. 

He needed to call someone. Someone strong enough to drag him out of the apartment before he did something you would hate him for. But his phone was still in the bag he’d dropped by the door, and when he pushed to his feet, they lead him in the opposite direction – towards your bedroom. 

There was a thunk when he let his head fall against your door. Your scent burned his nose, made his eyes water, but it tasted so fucking good on the back of his tongue. His chest hurt and his hands itched. He knew it would go away the moment your skin touched his. 

His teeth ached with the need to sink them into your neck. To mark you, permanently, as his. 

He squeezed his eyes shut. “Don’t go in there,” he growled to himself.

You must have heard him. Either that or you could smell him through the door – through your musk. The next thing he heard was your whine. “Bucky, please.”

The door jamb splintered when he wrenched it open. There you were, splayed out in the middle of your bed, naked as the day you were born. Your skin glistened with sweat. You were on your stomach, one knee drawn up, your ass tilted to the ceiling. There was a knotted dildo buried deep in your cunt, held in place by soft walls Bucky knew would be trying to milk it for the very thing that was making his own balls swell. Your fingers worked furiously on your clit.

Nothing seemed to be working for you. All you could do was sob into your pillow as you made a mess of your sheets. 

He didn’t know if it was his own free will or an invisible force that made it happen, but he found himself kneeling on the end of your bed and crawling over your body. He paused when he was braced over you, his fists sinking into the mattress on either side of your shoulders.

You drew in a deep breath as your sobs subsided. “Alpha,” you groaned as you pushed your ass up further. It brushed against the bulge in the front of his jeans. 

A deep growl vibrated through his chest as he lowered himself a few inches, enough that your ass pressed against him completely. 

The hand that had been working on your clit slithered up and wrapped around his flesh wrist. He closed his eyes when he felt your slick against his skin.

“No,” he said. He didn’t even recognise his own voice. “I’m not your Alpha.”

“Bucky,” you whined. “Please. It hurts so much.” 

You pushed your knee down so you were flat on your stomach. Your other hand wrapped around his metal wrist and you pushed your ass up even tighter against his cock. You rolled it against him. He thrust back with a growl, but when you tilted your hips even further and he felt something else press against him, he stopped and looked down. 

The handle of the dildo was slick with your juices, but he managed to get a hold of it and tug. You cried out when it didn’t budge.

“Omega,” Bucky growled. “Let it go.” A low whine slipped out of your mouth. He leant down until his lips brushed against your ear. “If you let it go, I’ll give your pretty little cunt something better to hold onto.”

Your teeth sank into your bottom lip as you writhed beneath him. Your muscles relaxed with the idea that you might finally be getting what you wanted. Bucky tugged again, and this time the dildo slid out. He threw it to the ground with an odd twang of jealousy. 

“Alpha,” you sighed.

Bucky pressed his forehead to the back of your shoulder, desperate to hold onto some semblance of control. He couldn’t do this, he reminded himself. You were his baby sister.

Maybe if he turned you over. At the moment, he could only see the back of your head and part of your profile. The rest of his view consisted of the curve of your back and your luscious, biteable ass. Maybe if he turned you over and saw your face – the face he’d grown up with – maybe that would give him pause. Remind him you were his sister.

He pushed back up, lifting his hips from yours and ignoring the needy whine you let out at the loss. 

“Turn over,” he said.

He was wrong. He was so fucking wrong. Whatever chance he’d had before, it was long gone. Blown out the fucking window and trampled to dust. Seeing your face did remind him that you were his baby sister – apparently, that’s what got him off. Not that you were an Omega, but that it was you. 

The little girl he’d protected. The one with pigtails that all the boys would pull on – all the boys he would beat up. The little girl he grew up with, watched grow into an awkward, smiling adolescent. The little girl he watched grow into a beautiful, strong woman. 

You were it – which meant he was doomed. There was no fixing him. 

You looked up at him, your brows furrowed, your lips red and raw from being chewed on. You opened your thighs for him, an invitation for him to wedge his hips between them. Still, he held himself above you. 

He shook his head. “We can’t.”

You smoothed your hands up his chest to curl around his neck and into his hair. “I missed you,” you whispered. “I thought you hated me.”

His heart dropped. “No. Baby girl … I could never hate you.”

Your eyes welled up. “You left me.”

He dropped down onto his forearms. Your lips parted when his jean-clad bulge pressed against your core. He didn’t let himself think about it. What he needed right now was to fix what he’d done. To make things right with you.

He cupped your face in his flesh hand, stroked his thumb over your bottom lip as he studied you. “It wasn’t your fault,” you said. “You didn’t do anything wrong, Y/N. I left because I love you.”

You rested your hands on either side of his face. “I love you, too.” 

He shook his head. “No. You don’t understand. I don’t love you like you’re my sister. It’s more than that.”

You reached down to grab two handfuls of his ass as you pushed your core up against him. He groaned and dropped his forehead to yours. Your nose brushed against his, you nipped his bottom lip.

“Touch me, Alpha,” you whispered. “Tell me I don’t feel the same.”

He shook his head as best he could against yours. He’d seen your glistening cunt when he walked in. He didn’t need to touch it to know how wet you were. Touching it would mean he’d crossed a line he couldn’t back away from.

It was almost laughable that he still believed he hadn’t crossed over that line.

“It’s just your heat,” he said. “You don’t want this. I can’t have this.”

You cupped his face again. “Bucky, look at me.” He drew his face back. His jaw was tight with everything he wanted to do and everything he couldn’t do. “It’s okay. We’re okay, Bucky. Look how calm you’ve already made me.” You guided his hand from your face to your chest. “I don’t feel so hot anymore. This is the most clear-headed I’ve been all week. I want this. I’ve always wanted this.”

“But –”

“Stop. We’re perfect together. We were made for each other. No other Alpha has been able to make me this calm in the middle of my heat by doing so little. Only you.”

His chest vibrated against your breasts with a growl. “Another Alpha touched you?”

You smiled. “See? I’m all there is for you. And you’re all there is for me. We both want this. We can have it – consequences be damned.”

It could have been your reassuring acceptance, or it could have been that fact that he realised he could lose you to another Alpha. Whatever it was, Bucky’s defences collapsed. 

He never imagined you could taste so sweet on his tongue, but as he kissed you, he couldn’t help but remember the cherry tree in the backyard of your childhood home. And as your hands slipped under his shirt, he remembered the beach he used to take you to. The way the waves caressed his skin and the warmth when the sun kissed it soon after. 

You were filled with all the memories Hydra took from him. Was it any wondered that he held onto you like you were the only thing keeping him alive?

You pulled at the clasp of his jeans and he lifted briefly to tear off his shirt. You were warm and soft against him. It awed him that no other woman had managed to make him feel this good, this loved, this safe … and he hadn’t even been inside you yet.

His jeans were pushed over his ass by your hands. It took a lot of squirming and grunts of impatience, but he managed to kick them the rest of the way off, along with his boots and socks. He lay bare against you and yet he’d never felt so secure. 

You stopped his hand when it snaked over your stomach. “I’ve been doing that all week. I just want you to knot me, Alpha, and make me yours for good.”

He had to admit, he regretted that he wouldn’t get to stretch your first time together out. That you just wanted to get him inside you. Many times, he had contemplated all the ways he would make you cum before he even thought of seeking his own satisfaction. All his life, all he ever wanted to do was make you happy – the bedroom was never going to be an exception. 

Nevertheless, he gave you what you wanted with a promise that he would make up that lost opportunity the moment you were ready. 

Bucky never much believed in a God, but the moment he buried himself inside you he damn near fucking believed in a heaven, and it was spread out in the bed beneath him – crying out his name and clinging to his shoulders.

“Fuck, Omega,” he growled. “You fit around me so damn good.”

He tried his best to make it last. He would moan as the head of his cock dragged along your walls, then he’d slam himself back into you, his control hanging on by a thread. He was far larger than you. His biceps themselves larger than both yours put together – no matter the size on your dress tags. He was built to be a hard giant of a man, the last thing he wanted to do was hurt you in the heat of the moment, but you seemed hell-bent on it. 

“Alpha, please. Fuck me. I need it,” you groaned. 

Your nails dug into his ass as you desperately tried to pull him against you. His body pinned yours to the mattress so you couldn’t thrust back against him. You nipped at the skin of his shoulder in a reprimand for being too gentle.

At last, he couldn’t take it anymore. With a growl, he hooked your knees over his elbows, adjusted his weight, and then he slammed home. Over and over again until finally no sound could escape your mouth and the convulsions around his cock seemed never-ending. 

Your hands came up to his face once more. Your body jolted with his hard thrusts. “Cum in me, Alpha. Please. Please. Please.”

He kissed you to silence the begging. You were his baby sister. His Omega. You never had to beg him for anything. His knot began to swell and catch at your entrance. Once. Twice. And then he was buried so deep inside you with no way out. He felt for a moment as though you were one person. Then his cock jumped and he was spilling into you with a rough moan. 

It was minutes before he’d softened enough to pull out of you. It was as though neither of your bodies was willing to let the other go. He had no problems with that. As he rolled to his side, he pulled you into him, drawing your thigh over his waist and slipping his metal arm beneath your pillow. 

You both lay there for a short while, your foreheads pressed together. Your fingers traced his jawline and his traced your spine.

“I’m sorry for leaving you,” he whispered at last. “I just … I didn’t know what to do. I thought it was best for you.”

“The only person who knows what’s best for me is me, Bucky,” you said. “You can make a damn good educated guess, but you don’t ever get to make a decision like that without me. You don’t get to just cut me out of your life without warning. Not after all we’ve been through together. You owe me more than that.”

“You’re right. It’ll never happen again. I promise.”

And it never did. After a long, whispered conversation amongst the pillows, Bucky claimed you that night. It was a neat bite, precise. It had been thought about, taken care of – the perfect representation of how Bucky had always and would always treat you.

**Author's Note:**

> I've got more fics at iavengesuperwholock.tumblr.com


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